Federal Aviation Administration

B737CL and B737NG Airdata

System Design Differences

13-15 September 2016

Yaghoob Ebrahimi

9/29/2016

Boeing 737

• Derived from the B707 and B727 technologies

• Narrow-body/single aisle airliner

• Developed into a family of 10+ models/derivatives

• Capacity of 85-220 passengers

• Boeing’s only single aisle airplane produced today

• The best selling airliner with 13533 firm orders (July 2016)

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The history of the B737 development(Cont’d)

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737-100

• First Flight: April 9, 1967

737-200

• First Flight: August 8, 1967

• 737-200 Advanced followed in 1971

B737CL:

• B737-300 First Flight February 24, 1984

• The -400 and -500 followed

B737NG:

• B737-700 First Flight February 9, 1997

• The -600, -800, -900 and -900ER followed

Images of the B737CL and B737NG cockpit

B737CL

B737CL cockpit

B737NG

B737NG cockpit resembles B777

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Pitot and static systems of aircraft

• The Pitot-static system is used to determine and display

Airspeed

Mach number

Altitude

Altitude trend

• Large Pitot-static system errors can be hazardous

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Pitot and static systems of aircraft

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• General system types used by Boeing

Model Airdata System Type

707                                                        FlushStatic (Not RVSM qualified by Boeing)

727                                                        Flush Static

737-100/-200/-300/-400/-500     Pitot-static (737-100 Not RVSM qualified by Boeing)

737-NG                                                Flush Static

737-700C                                             Pitot-static

737-MAX                                            Flush Static

747-100/-200/-300/-SR/-SP         Pitot-static (5inch)

747-400                                               Pitot-static (5inch/10inch)

747-8                                                    Pitot-static (10inch)

757                                                        Flush Static

767                                                        Pitot-static

777                         Flush Static

787                                                        Flush Static

Boeing Airplane Models ASERs

• B733 1

• B737 16

• B738 2

• B744 3

• B744-10 6

• B763 7

• B747-LCF 1

• B757 1

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Pitot and static systems of aircraft

• Must understand the details at the time of design to

better understand system selection

Configuration features and details

Future anticipated derivatives

Flight envelope

Corrections/type of corrections needed

Technology available

Certification demands

Cost/reliability

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B737CL Exhibits Larger ASE Average & SD vs. B737NG Reflects Older vs Newer Design and Build Requirements

and Some Shortcomings In The Ability to Monitor In Service

• AGHME Monitored data for 1/1/2011 to 1/1/2016 (5 Years))

• AGHME Monitored data for 1/1/2015 to 1/1/2016 (1 Year)

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Pitot and static systems of aircraft (Cont’d)

Different types/combination of pitot-static systems

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Pitot and static systems of aircraft (Cont’d)

Different types/combination of Pitot-static systems

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Pitot-Static Probe

737CL

Pitot with Flush Static

737NG

Pitot and static systems of the B737CL vs. B737NG

B737CL

• 4 Pitot-Static(P/S) Probes

• 2 Alternate Flush Static

Ports

B737NG

• 3 Pitot Probes

• 4 Flush Static Ports

• 2 Alternate Flush Static

Ports

• 2 Alpha Vanes

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Service Letter

(Skin Quality and Condition) B737CL

B737NG

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Approximate Number of B737CL & NG

Operating in North America

• The monitored data statistics of the FAA AGHME sites are summarized, 2010 through 2016 • Note: The Atlantic City and Portland sites were excluded.

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Model 2010 - 2012 2012 - 2014 2014 - 2016

B737CL 386 358 238

B737NG 650 893 1187

737 Service Letters

• 737-200

737-SL-02-015

• 08 Aug 1996

• Currently in revision

• 737-CL

737-SL-02-014

• 30 June 2004

• Currently in revision

• 737NG

737-SL-02-017

• 12 July 2016

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737 Service Letters B737CL

Initial in-service airworthiness

In support of B737CL qualification

for RVSM Boeing released SB 737-

53-1180 to assist the operators in

qualifying and maintaining their in-

service B737CL prior to line

number 2755. Upon the

incorporation of the SB and the

airplane flight manual revision

document individual airplane are

qualified for the RVSM airspace.

Airplanes delivered after position

number 2754 are RVSM qualified.

B737NG

Initial in-service airworthiness

The airplane flight manual

documents the eligibility of B737-

600/-700/-800/-900/BBJ/-700C

airplane type in RVSM airspace.

The referenced documents: MPD,

AMM and SRM provide the

necessary data to maintain

airworthiness compliance with the

RVSM requirements.

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ASE – Primary Error Sources

• Pitot-static Probes

Deterioration – erosion / corrosion

• Pressure Transducer

ADC

ADM

Failures or instability with time

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737 Recent Service Bulletins B737CL

737-200, 737-200C, 737-

300, 737-400, and 737-500

737-34-2454

NAVIGATION - Air Data

System - Altimetry System

Test

B737NG

737-600, 737-700, 737-700C, 737-800, 737-900

and 737-900ER

737-34-2642

NAVIGATION - Air Data

System - Altimetry System

Test

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